Future Hall of Famer and former two division unified champion Bernard Hopkins believes UFC superstar Conor McGregor should not be allowed to fight someone like Floyd Mayweather Jr. - who is still the biggest name in the sport.

A deal was finalized for Mayweather, 40, to return to the ring for a boxing match against McGregor, on August 26th from the T-Mobile Arena in Las Vegas.

Both athletes stand to make over $100 million from the Showtime pay-per-view showdown.

Hopkins can't believe that someone like McGregor - who has no experience in a boxing ring - would be allowed to fight someone like Mayweather, who is an undefeated former five division world champion and regarded as the best boxer of this generation.

Hopkins is offended that an athlete from another sport, would be allowed to receive the opportunity to make a nine figure payday without paying his dues in the sport.

"This is all fake news. First of all, he hasn't fought an amateur fight to my knowledge. I've checked around and I've been around the game for a long time. He hasn't had any experience as an amateur or a professional. How does any commission, in Vegas or anywhere, give him a license to fight a guy like Mayweather, who is one of the icon guys of our era," Hopkins said.

"How does he get that chance? Boxing should not let, we should not let, the people in business of boxing should not let a person to just walk right in and get the grand prize of boxing. You can't do it in basketball, football, hockey. It ruins the credibility [of boxing]."

Mayweather has no problem allowing McGregor to make a record amount of money. He views McGregor as a credible opponent - although nearly every expert has listed the MMA superstar as a massive underdog.

Hopkins believes Mayweather is sending a bad message by going along with the fight.

"That shows you the lack of respect that he has for the sport," Hopkins said.

Hopkins has a dog in the fight. He is a partner in Golden Boy Promotions, who three weeks later, on September 16th, also at T-Mobile Arena, are staging a massive event where Canelo Alvarez will challenge middleweight king Gennady Golovkin on HBO Pay-Per-View.

The fact that Mayweather-McGregor is taking place three weeks prior is certainly going to have some impact on the overall business, and pre-fight media coverage, for Canelo-Golovkin.